E.i. Dupont De Nemours and Company

David John Royall

John Arthur Turner

Duncan C Woodcock

Duncan Stuart Hugall

Roger Gaskell Fairhurst

Graham Howard Jones

Julie Ann Bartlett

An aromatic carboxylic acid such as terephthalic acid is produced by the liquid phase oxidation of a precursor thereof, the oxidation being carried out in such a way that substantially all of the aromatic carboxylic acid produced in the course of the reaction is maintained in solution during the reaction.

Production of terephthalic acid

Cobalt and/or manganese is recovered from the ash obtained following incineration of the catalyst containing residue arising from the liquid phase oxidation of an aromatic carboxylic acid such as terephthalic acid. Recovery is effected by contacting the ash with an organic acid or an organic acid anhydride such as acetic anhydride, optionally in the presence of bromide ions (e.g. HBr), so that the cobalt and/or manganese metals are recovered as monocarboxylic acid soluble salts thereof thus permitting recycle thereof to the liquid phase oxidation process.

Production of aromatic carboxylic acids and recovery of Co/Mn catalyst from ash

Growing community of inventors

Cleveland, United Kingdom

David John Royall